It is the successor to the vintage references 765 AVI, 765 Co-Pilot, and 7650 Co-Pilot, which measured well above 40mm some 50+ years ago, as they were first and foremost intended as tool watches for pilots. And in a cockpit, a larger diameter often allows for an increased legibility. Breitling was always careful to offer short lugs in order to avoid the watches feeling like a pizza on the wrist (although some 47mm vintage Breitlings are actually nicknamed the "Pizza," but this is a story for another time).
The Chronoliner B04 Boutique Edition retails for $9,150.
